using System;

​

public class Book {

  public Book(string name, Author author, string category) {

    this.name = name;

    this.author = author;

    this.category = category;

  }

  public string name;

  public Author author;

  public string category;

}

​

public class Author {

  public Author(string name) {

    this.name = name;

  }

  public string name;

}

public class Program

{

    public static void Main()

    {

        var jaafariGhomi = new Author("jaafari ghomi");

        var shabakeHaieComputeri = new Book("Shabake Haie Computeri", jaafariGhomi, "IT");

        Console.WriteLine(shabakeHaieComputeri.author.name);

        Console.WriteLine(shabakeHaieComputeri.name);

    }

}